1. Field of the Invention
The present invention relates to a camera which has a function for designating a print aspect ratio of a photo-print concurrently with photographing, and more particularly to a camera wherein a field of view of a viewfinder is changed to have the same aspect ratio as an effective picture area to be used for printing, while maintaining the vertical range of the field of view as well as that of a photographic field taken within the effective picture area substantially unchanged before and after changing the print aspect ratio.
2. Related Art
Some of recent 35 mm compact cameras for taking pictures in full-size on 35 mm photographic film, have a function for designating a print aspect ratio of a photo-print concurrently with photographing so as to change the print aspect ratio within the same photographic film.
There are two types of aspect ratio changing or selecting methods, namely, using a variable exposure opening type and using a fixed exposure opening type. In the variable exposure opening type, that is utilized, for example, in "Kardia Travel Mini" (a trademark) sold under the name of Fuji Photo Film Co., Ltd., a mechanical mask member or an LCD panel mask member is disposed in front of an exposure aperture of a camera, for actually changing the original frame size in accordance with the print aspect ratio. For example, a panoramic-size exposure frame of 13 mm.times.36 mm (aspect ratio: about 2.8) is provided by masking upper and lower portions of the exposure aperture which defines a 35 mm format full-size exposure frame of 24 mm.times.36 mm (aspect ratio: 1.5). An original taken in the panoramic-size exposure frame is printed at a magnification of about twice the magnification for a standard printing, so as to produce a panoramic print which is twice as long as a standard print.
in the fixed opening type, every original is taken in a full-size defined by a fixed exposure aperture, and an area of the original that corresponds to the print aspect ratio is printed by cropping. In this type, data of print aspect ratio or the area to be printed with the full-size frame is optically or magnetically recorded in association with the original to be cropped. Therefore, we use the phrase "an effective picture area" for the area to be printed within the full-size frame, and the phrase "a vertical angle of view" for an angle of view that is determined based on the height of the effective picture area and the focal length, and the phrase "a vertical range of photographic field" for the scenic range included in the effective picture area in the direction of height.
It is conventional in these types of cameras to display a frame in a field of view of a viewfinder, for indicating a photographic field corresponding to the effective picture area. For example, in "IZM 220 Panorama Zoom" (a trademark), when a panoramic photograph mode is selected, upper and lower portion of a field of view of the viewfinder are masked in black, while the field of view is a little widened in a horizontal direction, concurrently with the changing of the exposure frame into a panoramic size, which is effected by inserting a movable masking plates into the upper and lower portions of the exposure aperture.
Although the above-described conventional camera can perform a panoramic photography at any image magnification, the panoramic photography is merely to mask the upper and lower portion of the full-size exposure aperture or to crop the full-size original. Therefore, the panoramic-size photo-prints made from those originals do not actually cover a wider angle of view or a wider horizontal range than the standard-size photo-print made from the full-size original, and do not look so much like panoramic. Moreover, because the vertical range of the field of view is reduced for indicating the panoramic photographic field, it is inevitable to give an impression to the photographer that the field of view is rather confined than widened, even through the horizontal range of the field of view is a little enlarged. It certainly reduces the pleasure of taking panoramic photographs.